医用钛合金植入材料生物相容性改进方法及对成骨影响的研究
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摘要
随着新型医用钛合金植入材料不断应用于临床,解决了以往许多难以解决的问题,特别在骨科领域中,作为骨内植入体和硬组织修复材料的医用钛合金植入材料得到了广泛的临床应用。但是对于生物有机体而言,医用金属植入材料毕竟还是异物,其在物理和化学性能方面与体内环境还存在着巨大的区别。在现实的骨科临床应用中,这种金属材料自身性质的差异往往会带来很严重的问题。为了解决这些问题,人们开始着手研究如何提高医用钛合金植入材料的生物相容性,使植入体能够与周围的骨组织形成稳定的生物结合,保证植入体的近、远期效果。
对于骨科而言,我们所关心的植入金属材料生物相容性主要包括:材料与宿主之间的生物力学、物理化学方面的相互作用。表现为材料与宿主直接或间接接触时涉及组织接受与定向结合、应力传递与分布、材料表面生物学行为等等一系列生物学行为。对于骨科而言,我们最关心材料的力学特性和表面特性。因此,本研究拟从改善钛合金植入材料力学特性以及表面特性两方面入手,提高材料的生物相容性,并通过动物体内实验的方法检测其对于成骨的影响,以验证其生物相容性改善的情况。
对于材料力学特性的改善,我们选用新近研制具有国家自主知识产权的新型超低弹性模量钛合金Ti-24Nb-4Zr-7.9Sn,其弹性模量仅为33GPa[1]。因为根据以往的相关研究结果,弹性模量是决定金属植入材料骨组织内应力是否集中的重要参数,理论上,弹性模量越低、越接近骨,引起应力吸收的几率就越小,不良并发症发生的机率也就越小。在材料表面改性方面,我们选用50μm沟槽的规则微形态表面。在本课题组前期进行的动物体外实验中,我们对照观察了多种微形态表面上成骨细胞的生长情况。结果发现,50μm沟槽的规则微形态表面的细胞在生长、分化等方面均具有优势,所以同时作为前期体外实验的体内验证性研究,我们在表面处理上选择50μm规则微形态。
1.低弹性模量钛合金髓内针对兔胫骨骨折愈合及胫骨髓腔内成骨的影响
目的:为了检验低弹性模量金属植入材料对于成骨的影响,我们选择Ti-24Nb-4Zr-7.9Sn作为实验对象,选择目前临床最常用的钛合金Ti-6Al-4V作为对照,在兔胫骨骨折髓内针内固定模型中,检验这两种合金材料对于髓内针周围成骨及骨折愈合的影响。方法:实验选用新西兰大白兔15只,将Ti-24Nb-4Zr-7.9Sn(wt%)和Ti-6Al-4V(wt%)两种钛合金材料采用铸造和机械加工的方法制成直径为2mm、长度为85mm的圆棒,作为实验用的髓内针。胫骨做横行截骨后打入髓内针至胫骨骨髓腔以固定骨折,15只动物手术后均观察4周。术后当日及术后各周拍胫骨正侧位片,以确定内固定位置。手术后4周时,处死15只动物,随机选择5只做生物力学实验,5只拔除髓内针后做Micro-CT实验,5只带髓内针做病理学组织学观察。其中生物力学实验检测髓内针拔出力与骨折处骨痂的最大牵拉力,单位均为牛顿(N);Micro-CT实验测量胫骨远端髓内针周围的骨密度和骨痂体积比;组织病理切片使用MMA硬组织包埋,硬组织切片,HE染色和三色染色,并进行计算机辅助的图像分析计算骨痂面积比。数据统计采用SPSS 12.0进行双尾配对t检验,P值取0.05。结果:X线片示各只动物的骨折对位、内固定位置均良好,骨折线随时间变得逐渐模糊,骨痂量随时间增加,基本在第三周就已经有较明显骨痂覆盖骨折端。生物力学所得髓内针拔出力试验组与对照组分别为127.8±10.0N和110.9±7.9N,具有明显差异(P=0.009),而两组间骨痂最大牵拉力无明显差别(P=0.76)。从Micro-CT所得二维和三维图像可观察到明显的髓腔内成骨,BMD与BVF两组间均有明显差异。病理学图像分析所得的骨痂体积比有明显差异(P=0.00019)。结论:根据实验所得结果,可以证实低弹性模量髓内针内固定的Ti-24Nb-4Zr-7.9Sn实验组与Ti-6Al-4V对照组相比,在手术后的第四周,实验组胫骨髓腔内有较多的新骨形成,但是对于胫骨骨折愈合的影响并无差异。总之,通过本实验可以证实,低弹性模量金属植入材料对于周围成骨具有明显的促进作用。
2.表面规则微形态低弹性模量钛合金植入物对于兔胫骨内成骨的影响
目的:结合前一实验与本课题组前期实验的结果,我们计划进一步对比并验证不同表面以及处于不同生物应力条件下对于体内成骨的影响。将分别带有50μm规则微形态表面和光滑表面的Ti-24Nb-4Zr-7.9Sn与Ti-6Al-4V钛合金内植物植入兔胫骨中,观察手术后4周时表面新骨生成的情况。方法:实验选用新西兰大白兔5只,将Ti-24Nb-4Zr-7.9Sn(wt%)和Ti-6Al-4V(wt%)两种钛合金材料采用铸造和机械加工的方法制成制备成长0.5cm,厚1.0mm的正方形基片,在分别加工出50μm规则微形态表面和光滑表面,作为实验用的植入物,植入于胫骨中段。其中左侧两个开槽均放入Ti-24Nb-4Zr-7.9Sn植入物,右侧两个开槽均放入Ti-6Al-4V植入物;双侧胫骨上方的两个开槽均放入光滑表面植入物,下方的两个开槽均放入规则微纹理表面植入物。术后当日及术后各周拍胫骨正侧位片,以确定内固定位置。手术后4周时,处死的动物,取出胫骨标本分别使用Micro-CT检测BMD与BVF;再进行组织病理学分析,MMA硬组织包埋,硬组织切片,而后进行显微X线片观察、白色背景光视野观察、偏振光视野观察以及甲苯胺兰染色后观察,并进行计算机辅助的图像分析计算骨痂面积比。数据统计采用SPSS 12.0进行双尾配对t检验,P值取0.05。结果:从Micro-CT所得图像可观察到明显的表面成骨灰度影像,所测得的BMD与BVF进行统计后发现:在材料相同时,规则微纹理表面成骨较好,而表面相同时,低弹性模量钛合金周围成骨情况良好,Ti-6Al-4V植入物周围发生骨质吸收现象。分别通过显微X线片观察、白色背景光视野观察、偏振光视野观察以及甲苯胺兰染色后观察,一方面可以证实Micro-CT所得表面灰度影像确实为骨组织影像,另一方面也再次验证了Micro-CT截面图中所得到的结果。甲苯胺兰染色后,经过图像分析所得的骨痂体积比(BVF)与Micro-CT检测所的结果接近。结论:根据实验所得结果,可以证实在材料相同的前提下,50μm的规则微纹理与光滑表面相比,具有良好的成骨诱导作用;而表面条件相同时,具有低弹性模量的Ti-24Nb-4Zr-7.9Sn钛合金植入物对于成骨的影响优于目前临床广泛使用的Ti-6Al-4V钛合金。总之,通过本实验可以证实,低弹性模量金属植入材料所带来的低生物应力条件与50μm的规则微沟槽带来的微纹理表面环境对于成骨均具有良好的促进作用。
With more and more new kinds of medical metal implants applied in clinical work, many difficult problems are resolved. In the orthopaedics field, especially, medical metal implants are used widly in clinical application, such as implants for bone and repair materials for hard tissue repair. But metal implants are kinds of foreign bodies for living organism. There are very big differences between them on physical and chemical properties. In the orthopaedics clinical application, many serious problems are usualy due to these differences. To resolve these problems, the biocompatibility of medical metal implants is going to be improved in order to stable the connection between bone tissue and implants and ensure the long-term results of implants operation.
In the orthopaedics clinical application, the most two important biocompatibilities of medical metal implants are biomechanics and physical chemistry interaction between bone tissue and implants. It is showed a serial of biological behaviour, such as the integratation in direction, the transmission and location of stress, and biological behaviour on surface and so on. In a word, mechanics and surface properties of implants are concerned about seriously by orthipedist. So there two approaches to improve the biocompatibilities of medical metal implants in this study. One is to improve the mechanics property, and the other is surface property. After the modification, we compare the new implant with normal one applied in clinic to validate the effects of the modification using an animal model.
To improve the mechanics property, the intramedullary nails made of both Ti-24Nb-4Zr-7.9Sn alloy (weight percent) with elastic modulus ~33 GPa and the Ti-6Al-4V ELI alloy with modulus ~110 GPa were inserted into marrow cavity of rabbits to fix the fractured tibia. The early effect on healing of fracture tibia and new bone formation around the nails in the marrow cavity were investigated up to 4 weeks after implantation. To improve the surfce property, the micro-grooved surface is chosen. Our early investigation showed better cell proliferation and best cell differentiation on the micro-grooved surface at the cell scale (50μm), and osteoblastic cells on the micro-grooved surfaces also displayed a more similar morphology to osteoblastic cells in vivo. So the test surfaces are micro-grooved surface with the scale of 50μm and smooth surface.
1. Early Effect of Ti-24Nb-4Zr-7.9Sn Intramedullary Nails on Fractured Bone
Objective A multifunctional titanium alloy with ultra-low elastic modulus and high strength has been developed very recently for potential biomedical applications. In this study, the bone healing and stability of implants in a rabbit tibial fracture model were investigated using intramedullary nails made of either Ti-24Nb-4Zr-7.9Sn alloy or Ti-6Al-4V ELI.
Methods A total of 15 New Zealand white rabbits of both sexes were used as experimental animals. After tibial fracture along transverse direction was introduced in both sides of tibiae closing to the middle part, the nail was inserted into the marrow cavity. Postsurgerily and weekly, all the rabbits were examined weekly by X-ray. At the 4th week, 5 sacrificed rabbits were selected randomly to perform biomechanical testing including nails were pulled out test and callus tensile test. Other 5 rabbits were sacrificed randomly for Micro-CT analysis. The BMD and BVF were detected. The rest of last 5 rabbits were used for histological observations of the callus formation around the distal end of the tibiae. Two-tailed t-test was the one used for statistical analysis using SPSS software version 12 for windows (SPSS, Chicago, IL, USA). Statistical significance was set at a probability p<0.05.
Results The radiograph analyses showed that there were no signs of deformity in any of the fractured tibiae except the excluded four rabbits due to deep infection after implantations. The macroscopic observation also showed that the fracture lines of all rabbits almost disappeared by the generation of new callus around the fracture areas up to 4 weeks. The pull-out force of nails and tensile force of the newly formed callus located at the fracture site are presented in the Tab. 2. The mean pull-out forces of nails was 127.8N in experimental and 110.9N in control groups (p=0.009), showing significant statistical difference. However, the mean tensile force of the newly formed callus were almost identical being 172.3N and 170.7N (p=0.76) for both groups, showing no statistical difference. Quantitative data of bone regeneration obtained by the micro-CT analysis are given in Tab. 3. It shows that there was significant difference between the experimental and control groups. The mean BMD in experimental group is 197.3 mg/cm3 but 140.9 mg/cm3 in control group while the mean BVF is also higher in experimental group. Two and three dimensional micro-CT observations also show consistent results. After staining the cut slices by Masson trichrome, histological observation confirmed that the tissue around the implanted nails are new bone callus. The mean BVF in experimental group was 45.8% vs. 32.6% in control group, similar to the data obtained by BVF from micro-CT analysis.
Conclusion These results suggested that, in the early stage of fixation, the nails with ultra-low elastic modulus improved the new bone formation in the marrow cavity.
2. Effect of surface micro-topography of titanium test piece with low elastic modulus on new bone formation in tibea of rabbit
Objective From the results of test one, the advantage of Ti-24Nb-4Zr-7.9Sn could be see. To compare the effect of different alloies with different surface, Ti-24Nb-4Zr-7.9Sn and Ti-6Al-4V implamts with regulated micro-topography in 50μm and smooth surface were implanted into tibea of rabbit. After 4 weeks, new bone formations on surface were compared.
Methods 5 rabbits were used. Materials Ti-24Nb-4Zr-7.9Sn and Ti-6Al-4V were made into square implants with 0.5cm in length and 1.0mm in high. Two kinds of surface were made on both materials, and then 4 kinds of implants were implanted into the middle part of tebea of rabbit. There were 4 sites for 4 kinds of implants. Both Ti-24Nb-4Zr-7.9Sn implamts were put into left tibea and Ti-6Al-4V in right. Both smooth impalnts were put into upper sites, and micro-topography in lower sites. Postoperative radiograghy was made to ensure the position of implants. At the 4th week, all animals were sacrificed for Micro-CT and histopathology analysis. BMD and BVF were detected in Micro-CT. After embeded in MMA, tissue was sliced for micro-X-ray, white light, polarized light and toluidine blue observation. Computer image analysis was made for slice using toluidine blue stain. Two-tailed t-test was the one used for statistical analysis using SPSS software version 12 for windows (SPSS, Chicago, IL, USA). Statistical significance was set at a probability p<0.05.
Results The grayscale image of new bone formation could be seen clearly from Micro-CT. BMD and BVF analysis showed that the formation of new bone around micro-topography surface is better than smooth on and more new bone were seen around Ti-24Nb-4Zr-7.9Sn implants. Bone resorption was seen around the Ti-6Al-4V implants. From micro-X-ray, white light, polarized light and toluidine blue observation, the same results were seen. The images from histopathology analysis could ensure the grayscale image from Micro-CT. After toluidine blue stain, the BVF by computer image analysis was similar to Micro-CT.
Conclusion Compared to smooth surface, micro-topography with the scale of 50μm surface have better effect on induction for bone formation. In the condition of same surface, Ti-24Nb-4Zr-7.9Sn implants with low elatic modulus improved the new bone formation on the surface of implants in the marrow cavity. In a word, both low elatic modulus Ti alloy and micro-topography with the scale of 50μm have satisfactory promotive effects on new bone formation around implants.
对于骨科而言,我们所关心的植入金属材料生物相容性主要包括:材料与宿主之间的生物力学、物理化学方面的相互作用。表现为材料与宿主直接或间接接触时涉及组织接受与定向结合、应力传递与分布、材料表面生物学行为等等一系列生物学行为。对于骨科而言,我们最关心材料的力学特性和表面特性。因此,本研究拟从改善钛合金植入材料力学特性以及表面特性两方面入手,提高材料的生物相容性,并通过动物体内实验的方法检测其对于成骨的影响,以验证其生物相容性改善的情况。
对于材料力学特性的改善,我们选用新近研制具有国家自主知识产权的新型超低弹性模量钛合金Ti-24Nb-4Zr-7.9Sn,其弹性模量仅为33GPa[1]。因为根据以往的相关研究结果,弹性模量是决定金属植入材料骨组织内应力是否集中的重要参数,理论上,弹性模量越低、越接近骨,引起应力吸收的几率就越小,不良并发症发生的机率也就越小。在材料表面改性方面,我们选用50μm沟槽的规则微形态表面。在本课题组前期进行的动物体外实验中,我们对照观察了多种微形态表面上成骨细胞的生长情况。结果发现,50μm沟槽的规则微形态表面的细胞在生长、分化等方面均具有优势,所以同时作为前期体外实验的体内验证性研究,我们在表面处理上选择50μm规则微形态。
1.低弹性模量钛合金髓内针对兔胫骨骨折愈合及胫骨髓腔内成骨的影响
目的:为了检验低弹性模量金属植入材料对于成骨的影响,我们选择Ti-24Nb-4Zr-7.9Sn作为实验对象,选择目前临床最常用的钛合金Ti-6Al-4V作为对照,在兔胫骨骨折髓内针内固定模型中,检验这两种合金材料对于髓内针周围成骨及骨折愈合的影响。方法:实验选用新西兰大白兔15只,将Ti-24Nb-4Zr-7.9Sn(wt%)和Ti-6Al-4V(wt%)两种钛合金材料采用铸造和机械加工的方法制成直径为2mm、长度为85mm的圆棒,作为实验用的髓内针。胫骨做横行截骨后打入髓内针至胫骨骨髓腔以固定骨折,15只动物手术后均观察4周。术后当日及术后各周拍胫骨正侧位片,以确定内固定位置。手术后4周时,处死15只动物,随机选择5只做生物力学实验,5只拔除髓内针后做Micro-CT实验,5只带髓内针做病理学组织学观察。其中生物力学实验检测髓内针拔出力与骨折处骨痂的最大牵拉力,单位均为牛顿(N);Micro-CT实验测量胫骨远端髓内针周围的骨密度和骨痂体积比;组织病理切片使用MMA硬组织包埋,硬组织切片,HE染色和三色染色,并进行计算机辅助的图像分析计算骨痂面积比。数据统计采用SPSS 12.0进行双尾配对t检验,P值取0.05。结果:X线片示各只动物的骨折对位、内固定位置均良好,骨折线随时间变得逐渐模糊,骨痂量随时间增加,基本在第三周就已经有较明显骨痂覆盖骨折端。生物力学所得髓内针拔出力试验组与对照组分别为127.8±10.0N和110.9±7.9N,具有明显差异(P=0.009),而两组间骨痂最大牵拉力无明显差别(P=0.76)。从Micro-CT所得二维和三维图像可观察到明显的髓腔内成骨,BMD与BVF两组间均有明显差异。病理学图像分析所得的骨痂体积比有明显差异(P=0.00019)。结论:根据实验所得结果,可以证实低弹性模量髓内针内固定的Ti-24Nb-4Zr-7.9Sn实验组与Ti-6Al-4V对照组相比,在手术后的第四周,实验组胫骨髓腔内有较多的新骨形成,但是对于胫骨骨折愈合的影响并无差异。总之,通过本实验可以证实,低弹性模量金属植入材料对于周围成骨具有明显的促进作用。
2.表面规则微形态低弹性模量钛合金植入物对于兔胫骨内成骨的影响
目的:结合前一实验与本课题组前期实验的结果,我们计划进一步对比并验证不同表面以及处于不同生物应力条件下对于体内成骨的影响。将分别带有50μm规则微形态表面和光滑表面的Ti-24Nb-4Zr-7.9Sn与Ti-6Al-4V钛合金内植物植入兔胫骨中,观察手术后4周时表面新骨生成的情况。方法:实验选用新西兰大白兔5只,将Ti-24Nb-4Zr-7.9Sn(wt%)和Ti-6Al-4V(wt%)两种钛合金材料采用铸造和机械加工的方法制成制备成长0.5cm,厚1.0mm的正方形基片,在分别加工出50μm规则微形态表面和光滑表面,作为实验用的植入物,植入于胫骨中段。其中左侧两个开槽均放入Ti-24Nb-4Zr-7.9Sn植入物,右侧两个开槽均放入Ti-6Al-4V植入物;双侧胫骨上方的两个开槽均放入光滑表面植入物,下方的两个开槽均放入规则微纹理表面植入物。术后当日及术后各周拍胫骨正侧位片,以确定内固定位置。手术后4周时,处死的动物,取出胫骨标本分别使用Micro-CT检测BMD与BVF;再进行组织病理学分析,MMA硬组织包埋,硬组织切片,而后进行显微X线片观察、白色背景光视野观察、偏振光视野观察以及甲苯胺兰染色后观察,并进行计算机辅助的图像分析计算骨痂面积比。数据统计采用SPSS 12.0进行双尾配对t检验,P值取0.05。结果:从Micro-CT所得图像可观察到明显的表面成骨灰度影像,所测得的BMD与BVF进行统计后发现:在材料相同时,规则微纹理表面成骨较好,而表面相同时,低弹性模量钛合金周围成骨情况良好,Ti-6Al-4V植入物周围发生骨质吸收现象。分别通过显微X线片观察、白色背景光视野观察、偏振光视野观察以及甲苯胺兰染色后观察,一方面可以证实Micro-CT所得表面灰度影像确实为骨组织影像,另一方面也再次验证了Micro-CT截面图中所得到的结果。甲苯胺兰染色后,经过图像分析所得的骨痂体积比(BVF)与Micro-CT检测所的结果接近。结论:根据实验所得结果,可以证实在材料相同的前提下,50μm的规则微纹理与光滑表面相比,具有良好的成骨诱导作用;而表面条件相同时,具有低弹性模量的Ti-24Nb-4Zr-7.9Sn钛合金植入物对于成骨的影响优于目前临床广泛使用的Ti-6Al-4V钛合金。总之,通过本实验可以证实,低弹性模量金属植入材料所带来的低生物应力条件与50μm的规则微沟槽带来的微纹理表面环境对于成骨均具有良好的促进作用。
With more and more new kinds of medical metal implants applied in clinical work, many difficult problems are resolved. In the orthopaedics field, especially, medical metal implants are used widly in clinical application, such as implants for bone and repair materials for hard tissue repair. But metal implants are kinds of foreign bodies for living organism. There are very big differences between them on physical and chemical properties. In the orthopaedics clinical application, many serious problems are usualy due to these differences. To resolve these problems, the biocompatibility of medical metal implants is going to be improved in order to stable the connection between bone tissue and implants and ensure the long-term results of implants operation.
In the orthopaedics clinical application, the most two important biocompatibilities of medical metal implants are biomechanics and physical chemistry interaction between bone tissue and implants. It is showed a serial of biological behaviour, such as the integratation in direction, the transmission and location of stress, and biological behaviour on surface and so on. In a word, mechanics and surface properties of implants are concerned about seriously by orthipedist. So there two approaches to improve the biocompatibilities of medical metal implants in this study. One is to improve the mechanics property, and the other is surface property. After the modification, we compare the new implant with normal one applied in clinic to validate the effects of the modification using an animal model.
To improve the mechanics property, the intramedullary nails made of both Ti-24Nb-4Zr-7.9Sn alloy (weight percent) with elastic modulus ~33 GPa and the Ti-6Al-4V ELI alloy with modulus ~110 GPa were inserted into marrow cavity of rabbits to fix the fractured tibia. The early effect on healing of fracture tibia and new bone formation around the nails in the marrow cavity were investigated up to 4 weeks after implantation. To improve the surfce property, the micro-grooved surface is chosen. Our early investigation showed better cell proliferation and best cell differentiation on the micro-grooved surface at the cell scale (50μm), and osteoblastic cells on the micro-grooved surfaces also displayed a more similar morphology to osteoblastic cells in vivo. So the test surfaces are micro-grooved surface with the scale of 50μm and smooth surface.
1. Early Effect of Ti-24Nb-4Zr-7.9Sn Intramedullary Nails on Fractured Bone
Objective A multifunctional titanium alloy with ultra-low elastic modulus and high strength has been developed very recently for potential biomedical applications. In this study, the bone healing and stability of implants in a rabbit tibial fracture model were investigated using intramedullary nails made of either Ti-24Nb-4Zr-7.9Sn alloy or Ti-6Al-4V ELI.
Methods A total of 15 New Zealand white rabbits of both sexes were used as experimental animals. After tibial fracture along transverse direction was introduced in both sides of tibiae closing to the middle part, the nail was inserted into the marrow cavity. Postsurgerily and weekly, all the rabbits were examined weekly by X-ray. At the 4th week, 5 sacrificed rabbits were selected randomly to perform biomechanical testing including nails were pulled out test and callus tensile test. Other 5 rabbits were sacrificed randomly for Micro-CT analysis. The BMD and BVF were detected. The rest of last 5 rabbits were used for histological observations of the callus formation around the distal end of the tibiae. Two-tailed t-test was the one used for statistical analysis using SPSS software version 12 for windows (SPSS, Chicago, IL, USA). Statistical significance was set at a probability p<0.05.
Results The radiograph analyses showed that there were no signs of deformity in any of the fractured tibiae except the excluded four rabbits due to deep infection after implantations. The macroscopic observation also showed that the fracture lines of all rabbits almost disappeared by the generation of new callus around the fracture areas up to 4 weeks. The pull-out force of nails and tensile force of the newly formed callus located at the fracture site are presented in the Tab. 2. The mean pull-out forces of nails was 127.8N in experimental and 110.9N in control groups (p=0.009), showing significant statistical difference. However, the mean tensile force of the newly formed callus were almost identical being 172.3N and 170.7N (p=0.76) for both groups, showing no statistical difference. Quantitative data of bone regeneration obtained by the micro-CT analysis are given in Tab. 3. It shows that there was significant difference between the experimental and control groups. The mean BMD in experimental group is 197.3 mg/cm3 but 140.9 mg/cm3 in control group while the mean BVF is also higher in experimental group. Two and three dimensional micro-CT observations also show consistent results. After staining the cut slices by Masson trichrome, histological observation confirmed that the tissue around the implanted nails are new bone callus. The mean BVF in experimental group was 45.8% vs. 32.6% in control group, similar to the data obtained by BVF from micro-CT analysis.
Conclusion These results suggested that, in the early stage of fixation, the nails with ultra-low elastic modulus improved the new bone formation in the marrow cavity.
2. Effect of surface micro-topography of titanium test piece with low elastic modulus on new bone formation in tibea of rabbit
Objective From the results of test one, the advantage of Ti-24Nb-4Zr-7.9Sn could be see. To compare the effect of different alloies with different surface, Ti-24Nb-4Zr-7.9Sn and Ti-6Al-4V implamts with regulated micro-topography in 50μm and smooth surface were implanted into tibea of rabbit. After 4 weeks, new bone formations on surface were compared.
Methods 5 rabbits were used. Materials Ti-24Nb-4Zr-7.9Sn and Ti-6Al-4V were made into square implants with 0.5cm in length and 1.0mm in high. Two kinds of surface were made on both materials, and then 4 kinds of implants were implanted into the middle part of tebea of rabbit. There were 4 sites for 4 kinds of implants. Both Ti-24Nb-4Zr-7.9Sn implamts were put into left tibea and Ti-6Al-4V in right. Both smooth impalnts were put into upper sites, and micro-topography in lower sites. Postoperative radiograghy was made to ensure the position of implants. At the 4th week, all animals were sacrificed for Micro-CT and histopathology analysis. BMD and BVF were detected in Micro-CT. After embeded in MMA, tissue was sliced for micro-X-ray, white light, polarized light and toluidine blue observation. Computer image analysis was made for slice using toluidine blue stain. Two-tailed t-test was the one used for statistical analysis using SPSS software version 12 for windows (SPSS, Chicago, IL, USA). Statistical significance was set at a probability p<0.05.
Results The grayscale image of new bone formation could be seen clearly from Micro-CT. BMD and BVF analysis showed that the formation of new bone around micro-topography surface is better than smooth on and more new bone were seen around Ti-24Nb-4Zr-7.9Sn implants. Bone resorption was seen around the Ti-6Al-4V implants. From micro-X-ray, white light, polarized light and toluidine blue observation, the same results were seen. The images from histopathology analysis could ensure the grayscale image from Micro-CT. After toluidine blue stain, the BVF by computer image analysis was similar to Micro-CT.
Conclusion Compared to smooth surface, micro-topography with the scale of 50μm surface have better effect on induction for bone formation. In the condition of same surface, Ti-24Nb-4Zr-7.9Sn implants with low elatic modulus improved the new bone formation on the surface of implants in the marrow cavity. In a word, both low elatic modulus Ti alloy and micro-topography with the scale of 50μm have satisfactory promotive effects on new bone formation around implants.
引文
1. Hao YL, Li SJ, Sun SY, Zheng CY, Yang R. Elastic deformation behaviour of Ti-24Nb-4Zr-7.9Sn for biomedical applications. Acta Biomater 2007 Mar;3(2):277-286.
2. Wagner H, Wagner M. Conus hip prosthesis. Acta Chir Orthop Traumatol Cech2001;68(4):213-221.
3. Head WC, Bauk DJ, Emerson RH, Jr. Titanium as the material of choice for cementless femoral components in total hip arthroplasty. Clin Orthop Relat Res 1995Feb(311):85-90.
4. Nakajima H, Okabe T. Titanium in dentistry: development and research in the U.S.A. Dent Mater J 1996 Dec;15(2):77-90.
5. Akagi K, Okamoto Y, Matsuura T, Horibe T. Properties of test metal ceramic titanium alloys. J Prosthet Dent 1992 Sep;68(3):462-467.
6. Pang IC, Gilbert JL, Chai J, Lautenschlager EP Bonding characteristics of low-fusing porcelain bonded to pure titanium and palladium-copper alloy. J Prosthet Dent 1995 Jan;73(l): 17-25.
7. Pang IC, Gilbert JL, Lautenschlager EP, Chai JY Bonding characteristics of low-fusing porcelain to titanium and palladium-copper alloy. Northwest Dent Res 1994 Winter;4(2): 15-16.
8. Esquivel JF, Chai J, Wozniak WT. Color stability of low-fusing porcelains for titanium. Int J Prosthodont 1995 Sep-Oct;8(5):479-485.
9. Esquivel JF, Chai J, Wozniak WT. The physical properties of low-fusing porcelains for titanium. Int J Prosthodont 1996 Nov-Dec;9(6):563-571.
10. Eisenbarth E, Linez P, Biehl V, Velten D, Breme J, Hildebrand HF. Cellorientation and cytoskeleton organisation on ground titanium surfaces. Biomol Eng 2002 Aug;19(2-6):233-237.
11. Bowers KT, Keller JC, Randolph BA, Wick DG, Michaels CM. Optimization of surface micromorphology for enhanced osteoblast responses in vitro. Int J Oral Maxillofac Implants 1992 Fall;7(3):302-310.
12. Kawahara H. Cellular responses to implant materials: biological, physical and chemical factors. Int Dent J 1983 Dec;33(4):350-375.
13. Srimaneepong V, Yoneyama T, Kobayashi E, Doi H, Hanawa T. Comparative study on torsional strength, ductility and fracture characteristics of laser-welded alpha+beta Ti-6Al-7Nb alloy, CP Titanium and Co-Cr alloy dental castings. Dent Mater 2007 Dec 1.
14. Undisz A, Schrempel F, Wesch W, Rettenmayr M. In situ observation of surface oxide layers on medical grade Ni-Ti alloy during straining. J Biomed Mater Res A 2008 Apr 2.
15. Pun DK, Berzins DW. Corrosion behavior of shape memory, superelastic, and nonsuperelastic nickel-titanium-based orthodontic wires at various temperatures. Dent Mater 2008 Feb;24(2):221-227.
16. Suzuki A, Kanetaka H, Shimizu Y, Tomizuka R, Hosoda H, Miyazaki S, et al. Orthodontic buccal tooth movement by nickel-free titanium-based shape memory and superelastic alloy wire. Angle Orthod 2006 Nov;76(6): 1041-1046.
17. Tsao AK, Roberson JR, Christie MJ, Dore DD, Heck DA, Robertson DD, et al. Biomechanical and clinical evaluations of a porous tantalum implant for the treatment of early-stage osteonecrosis. J Bone Joint Surg Am 2005;87 Suppl 2:22-27.
18. Tsao AK, Dias LS, Conway JJ, Straka P. The prognostic value and significance of serial bone scintigraphy in Legg-Calve-Perthes disease. J PediatrOrthop 1997 Mar-Apr; 17(2):230-239.
19. Jandhyala BS, Horn GJ. Minireview: physiological and pharmacological properties of vanadium. Life Sci 1983 Oct 3;33(14): 1325-1340.
20. Hao YL, Li SJ, Sun BB, Sui ML, Yang R. Ductile titanium alloy with low Poisson's ratio. Phys Rev Lett 2007 May 25;98(21):216405.
21. Mostardi RA, Meerbaum SO, Kovacik MW, Gradisar IA, Jr. Response of human fibroblasts to tantalum and titanium in cell culture. Biomed Sci Instrum 1997;33:514-518.
22. Bhattarai SR, Khalil KA, Dewidar M, Hwang PH, Yi HK, Kim HY. Novel production method and in-vitro cell compatibility of porous Ti-6A1-4V alloy disk for hard tissue engineering. J Biomed Mater Res A 2007 Oct 23.
23. Dalmiglio M, Schaaff P, Holzwarth U, Chiesa R, Rondelli G The effect of surface treatments on the fretting behavior of Ti-6A1-4V alloy. J Biomed Mater Res B Appl Biomater 2007 Dec 27.
24. Li SJ, Niinomi M, Akahori T, Kasuga T, Yang R, Hao YL. Fatigue characteristics of bioactive glass-ceramic-coated Ti-29Nb-13Ta-4.6Zr for biomedical application. Biomaterials 2004 Aug;25(17):3369-3378.
25. Li SJ, Yang R, Niinomi M, Hao YL, Cui YY Formation and growth of calcium phosphate on the surface of oxidized Ti-29Nb-13Ta-4.6Zr alloy. Biomaterials 2004 Jun;25(13):2525-2532.
26. Mustafa K, Wennerberg A, Wroblewski J, Hultenby K, Lopez BS, Arvidson K. Determining optimal surface roughness of TiO(2) blasted titanium implant material for attachment, proliferation and differentiation of cells derived from human mandibular alveolar bone. Clin Oral Implants Res 2001 Oct;12(5):515-525.
27. Daugaard H, Elmengaard B, Bechtold JE, Soballe K. Bone growthenhancement in vivo on press-fit titanium alloy implants with acid etched microtexture. J Biomed Mater Res A 2008 Jan 9.
28. Eckardt A, Aberman HM, Cantwell HD, Heine J. Biological fixation of hydroxyapatite-coated versus grit-blasted titanium hip stems: a canine study. Arch Orthop Trauma Surg 2003 Feb;123(l):28-35.
29. Balcik C, Tokdemir T, Senkoylu A, Koc N, Timucin M, Akin S, et al. Early weight bearing of porous HA/TCP (60/40) ceramics in vivo: a longitudinal study in a segmental bone defect model of rabbit. Acta Biomater 2007 Nov;3(6):985-996.
30. Wang H, Eliaz N, Xiang Z, Hsu HP, Spector M, Hobbs LW. Early bone apposition in vivo on plasma-sprayed and electrochemically deposited hydroxyapatite coatings on titanium alloy. Biomaterials 2006 Aug;27(23):4192-4203.
31. Stewart M, Welter JF, Goldberg VM. Effect of hydroxyapatite/tricalcium-phosphate coating on osseointegration of plasma-sprayed titanium alloy implants. J Biomed Mater Res A 2004 Apr
32. Brunski JB. In vivo bone response to biomechanical loading at the bone/dental-implant interface. Adv Dent Res 1999 Jun; 13:99-119.
33. Iezzi G, Scarano A, Petrone G, Piattelli A. Two human hydroxyapatite-coated dental implants retrieved after a 14-year loading period: a histologic and histomorphometric case report. J Periodontol 2007 May;78(5):940-947.
34. Zhu X, Eibl O, Scheideler L, Geis-Gerstorfer J. Characterization of nano hydroxyapatite/collagen surfaces and cellular behaviors. J Biomed Mater Res A 2006 Oct;79(l): 114-127.
35. Wu Y, Yang BC, Deng CL, Tan YF, Zhang XD. The influence of surfacebioactivated modification on titanium percutaneous implants anchored in bone. Int JArtif Organs 2006 Jun;29(6):630-638.
36. Rokkum M, Reigstad A, Johansson CB, Albrektsson T. Tissue reactions adjacent to well-fixed hydroxyapatite-coated acetabular cups. Histopathology of ten specimens retrieved at reoperation after 0.3 to 5.8 years. J Bone Joint Surg Br 2003 Apr;85(3):440-447.
37. Itokawa H, Hiraide T, Moriya M, Fujimoto M, Nagashima G, Suzuki R, et al. A 12 month in vivo study on the response of bone to a hydroxyapatite-polymethylmethacrylate cranioplasty composite. Biomaterials 2007 Nov;28(33):4922-4927.
38. Beekmans HC, Meijer GJ, Barkhuysen R, Blijdorp PA, Merkx MA, Jansen J. The hydroxylapatite-bone interface: 10 years after implant installation. Int J Oral Maxillofac Surg 2008 Apr 8.
39. Eriksson C, Malmberg P, Nygren H. Time-of-flight secondary ion mass spectrometric analysis of the interface between bone and titanium implants. Rapid Commun Mass Spectrom 2008;22(7):943-949.
40. Davidson JA, Daigle KP, Kovacs P. Wear-resistant, hemocompatible Ti-Nb-Zr and Zr-Nb alloys to improve blood pump design and performance. Artif Organs 1996 Jun;20(6):513-522.
41. Davidson JA, Mishra AK, Kovacs P, Poggie RA. New surface-hardened, low-modulus, corrosion-resistant Ti-13Nb-13Zr alloy for total hip arthroplasty. Biomed Mater Eng 1994;4(3):231-243.
42. Gordin DM, Gloriant T, Texier G, Thibon I, Ansel D, Duval JL, et al. Development of a beta-type Ti-12Mo-5Ta alloy for biomedical applications: cytocompatibility and metallurgical aspects. J Mater Sci Mater Med 2004 Aug;15(8):885-891.
43. Hedia HS. Comparison of one-dimensional and two-dimensional functionally graded materials for the backing shell of the cemented acetabular cup. J Biomed Mater Res B Appl Biomater 2005 Aug;74(2):732-739.
44. Krishna BV, Bose S, Bandyopadhyay A. Low stiffness porous Ti structures for load-bearing implants. Acta Biomater 2007 Nov;3(6):997-1006.
45. Lefaix H, Asselin A, Vermaut P, Sautier JM, Berdal A, Portier R, et al. On the biocompatibility of a novel Ti-based amorphous composite: structural characterization and in-vitro osteoblasts response. J Mater Sci Mater Med 2008 May;19(5):1861-1869.
46. Lin DJ, Chuang CC, Chern Lin JH, Lee JW, Ju CP, Yin HS. Bone formation at the surface of low modulus Ti-7.5Mo implants in rabbit femur. Biomaterials 2007 Jun;28(16):2582-2589.
47. Nelea V, Pelletier H, Iliescu M, Werckmann J, Craciun V, Mihailescu IN, et al. Calcium phosphate thin film processing by pulsed laser deposition and in situ assisted ultraviolet pulsed laser deposition. J Mater Sci Mater Med 2002 Dec;13(12):1167-1173.
48. Nicula R, Luthen F, Stir M, Nebe B, Burkel E. Spark plasma sintering synthesis of porous nanocrystalline titanium alloys for biomedical applications. Biomol Eng 2007 Nov;24(5):564-567.
49. Sumitomo N, Noritake K, Hattori T, Morikawa K, Niwa S, Sato K, et al. Experiment study on fracture fixation with low rigidity titanium alloy : Plate fixation of tibia fracture model in rabbit. J Mater Sci Mater Med 2008 Apr;19(4):1581-1586.
50. Xue W, Krishna BV, Bandyopadhyay A, Bose S. Processing and biocompatibility evaluation of laser processed porous titanium. Acta Biomater 2007 Nov;3(6): 1007-1018.
51. Majzoub Z, Finotti M, Miotti F, Giardino R, Aldini NN, Cordioli G. Bone response to orthodontic loading of endosseous implants in the rabbit calvaria: early continuous distalizing forces. Eur J Orthod 1999 Jun;21(3):223-230.
52. Majzoub Z, Berengo M, Giardino R, Aldini NN, Cordioli G. Role of intramarrow penetration in osseous repair: a pilot study in the rabbit calvaria. J Periodontol 1999 Dec;70(12):1501-1510.
53. Weidong Z, Qibin L, Min Z, Xudong W. Biocompatibility of a functionally graded bioceramic coating made by wide-band laser cladding. J Biomed Mater Res A 2008 Jan 9.
54. Ko HC, Han JS, Bachle M, Jang JH, Shin SW, Kim DJ. Initial osteoblast-like cell response to pure titanium and zirconia/alumina ceramics. Dent Mater 2007 Nov;23(ll):1349-1355.
55. Zhao G, Schwartz Z, Wieland M, Rupp F, Geis-Gerstorfer J, Cochran DL, et al. High surface energy enhances cell response to titanium substrate microstructure. J Biomed Mater Res A 2005 Jul l;74(l):49-58.
56. Mahachoklertwattana P, Chuansumrit A, Sirisriro R, Choubtum L, Sriphrapradang A, Rajatanavin R. Bone mineral density, biochemical and hormonal profiles in suboptimally treated children and adolescents with beta-thalassaemia disease. Clin Endocrinol (Oxf) 2003 Mar;58(3):273-279.
57. Boyan BD, Lossdorfer S, Wang L, Zhao G, Lohmann CH, Cochran DL, et al. Osteoblasts generate an osteogenic microenvironment when grown on surfaces with rough microtopographies. Eur Cell Mater 2003 Oct 24;6:22-27.
58. Elias KL, Daehn GS, Brantley WA, McGlumphy EA. An initial study of diffusion bonds between superplastic Ti-6A1-4V for implant dentistry applications. J Prosthet Dent 2007 Jun;97(6):357-365.
59. Zhang LC, Zhou T, Alpay SP, Aindow M, Wu MH. Origin of pseudoelasticbehavior in Ti—Mo-based alloys. Applied Physics Letters 2005;87(24):241909-241903.
60. Li SJ, Cui TC, Hao YL, Yang R. Fatigue properties of a metastable beta-type titanium alloy with reversible phase transformation. Acta Biomater 2008 Mar;4(2):305-317.
61. Bobyn JD, Pilliar RM, Cameron HU, Weatherly GC. Osteogenic phenomena across endosteal bone-implant spaces with porous surfaced intramedullary implants. Acta Orthop Scand 1981;52(2): 145-153.
62. Bobyn JD, Pilliar RM, Cameron HU, Weatherly GC. The optimum pore size for the fixation of porous-surfaced metal implants by the ingrowth of bone. Clin Orthop Relat Res 1980 Jul-Aug(150):263-270.
63. Bobyn JD, Pilliar RM, Cameron HU, Weatherly GC, Kent GM. The effect of porous surface configuration on the tensile strength of fixation of implants by bone ingrowth. Clin Orthop Relat Res 1980 Jun(149):291-298.
64. Boyan BD, Lincks J, Lohmann CH, Sylvia VL, Cochran DL, Blanchard CR, et al. Effect of surface roughness and composition on costochondral chondrocytes is dependent on cell maturation state. J Orthop Res 1999 May;17(3):446-457.
65. Keselowsky BG, Wang L, Schwartz Z, Garcia AJ, Boyan BD. Integrin alpha(5) controls osteoblastic proliferation and differentiation responses to titanium substrates presenting different roughness characteristics in a roughness independent manner. J Biomed Mater Res A 2007 Mar l;80(3):700-710.
66. Marinucci L, Balloni S, Becchetti E, Belcastro S, Guerra M, Calvitti M, et al. Effect of titanium surface roughness on human osteoblast proliferation and gene expression in vitro. Int J Oral Maxillofac Implants 2006 Sep-Oct;21(5):719-725.
67. Martin JY, Dean DD, Cochran DL, Simpson J, Boyan BD, Schwartz Z. Proliferation, differentiation, and protein synthesis of human osteoblast-like cells(MG63) cultured on previously used titanium surfaces. Clin Oral Implants Res 1996Mar;7(l):27-37.
68. Rovensky Yu A, Domnina LV, Ivanova O, Vasiliev JM. Responses of epithelial and fibroblast-like cells to discontinuous configuration of the culture substrate. Membr Cell Biol 2001 Jul;14(5):617-627.
69. Levina EM, Domnina LV, Rovensky YA, Vasiliev JM. Cylindrical substratum induces different patterns of actin microfilament bundles in nontransformed and in ras-transformed epitheliocytes. Exp Cell Res 1996 Nov 25;229(1): 159-165.
70. Rovensky YA. The formation of filopodia-like protrusions during preparation of cell suspensions for scanning electron microscopy. Scanning Microsc 1995;9(4): 1223-1230; discussion 1230-1222.
71. Rovensky Yu A, Samoilov VI. Morphogenetic response of cultured normal and transformed fibroblasts, and epitheliocytes, to a cylindrical substratum surface. Possible role for the actin filament bundle pattern. J Cell Sci 1994 May;107(Pt5):1255-1263.
72. Rovensky YA, Komissarova EV, Topol LZ, Kisseljov FL. Changes in surface relief of suspended cells are morphological signs of the initial stage of neoplastic transformation in fibroblastic monolayer cultures. Cell Biol Int Rep 1992 Jun;16(6):557-565.
73. Piattelli A, Trisi P, Passi P, Piattelli M, Cordioli GP Histochemical and confocal laser scanning microscopy study of the bone-titanium interface: an experimental study in rabbits. Biomaterials 1994 Feb;15(3):194-200.
74. Hartwig D, Harloff S, Liu L, Schlenke P, Wedel T, Geerling G Epitheliotrophic capacity of a growth factor preparation produced from platelet concentrates on corneal epithelial cells: a potential agent for the treatment of ocular surface defects? Transfusion 2004 Dec;44(12): 1724-1731.
75. Hartwig CH, Rehak L, Milz S, Benner KU, Kusswetter W, Willmann G. [Osseointegration of titanium test bodies of different surface properties in metaphyseal bone sites of the dog~a biomechanical and histological analysis]. Biomed Tech (Berl) 1995 Apr;40(4):99-105.
76. Cordioli G, Atiyeh F, Piattelli A, Majzoub Z. Healing of transplanted composite bone grafts-implants: a pilot animal study. Clin Oral Implants Res 2003 Dec;14(6):750-758.
77. Cordioli G, Majzoub Z, Piattelli A, Scarano A. Removal torque and histomorphometric investigation of 4 different titanium surfaces: an experimental study in the rabbit tibia. Int J Oral Maxillofac Implants 2000 Sep-Oct;15(5):668-674.
78. Chierico A, Valentini R, Majzoub Z, Piattelli A, Scarano A, Okun L, et al. Electrically charged GTAM membranes stimulate osteogenesis in rabbit calvarial defects. Clin Oral Implants Res 1999 Oct;10(5):415-424.
79. Abrahamsson I, Albouy JP, Berglundh T. Healing at fluoride-modified implants placed in wide marginal defects: an experimental study in dogs. Clin Oral Implants Res 2008 Feb;19(2):153-159.
80. Abrahamsson I, Cardaropoli G. Peri-implant hard and soft tissue integration to dental implants made of titanium and gold. Clin Oral Implants Res 2007 Jun;18(3):269-274.
81. Abrahamsson I, Berglundh T. Tissue characteristics at microthreaded implants: an experimental study in dogs. Clin Implant Dent Relat Res 2006;8(3):107-113.
82. Abrahamsson I, Berglundh T, Linder E, Lang NP, Lindhe J. Early bone formation adjacent to rough and turned endosseous implant surfaces. An experimental study in the dog. Clin Oral Implants Res 2004 Aug;15(4):381-392.
83. Abrahamsson I, Berglundh T, Sekino S, Lindhe J. Tissue reactions to abutment shift: an experimental study in dogs. Clin Implant Dent Relat Res 2003;5(2):82-88.
84. Tsutsumi R, Hock C, Bechtold CD, Proulx ST, Bukata SV, Ito H, et al. Differential effects of biologic versus bisphosphonate inhibition of wear debris-induced osteolysis assessed by longitudinal micro-CT. J Orthop Res 2008 Apr 10.
85. Xu S, Lin K, Wang Z, Chang J, Wang L, Lu J, et al. Reconstruction of calvarial defect of rabbits using porous calcium silicate bioactive ceramics. Biomaterials 2008 Jun;29(17):2588-2596.
86. Voor MJ, Yang S, Burden RL, Waddell SW. In vivo micro-CT scanning of a rabbit distal femur: repeatability and reproducibility. J Biomech 2008;41(l):186-193.
87. Anumula S, Magland J, Wehrli SL, Ong H, Song HK, Wehrli FW. Multi-modality study of the compositional and mechanical implications of hypomineralization in a rabbit model of osteomalacia. Bone 2008 Feb;42(2):405-413.
88. Zhang G, Qin L, Sheng H, Yeung KW, Yeung HY, Cheung WH, et al. Epimedium-derived phytoestrogen exert beneficial effect on preventing steroid-associated osteonecrosis in rabbits with inhibition of both thrombosis and lipid-deposition. Bone 2007 Mar;40(3):685-692.
89. Swieszkowski W, Tuan BH, Kurzydlowski KJ, Hutmacher DW. Repair and regeneration of osteochondral defects in the articular joints. Biomol Eng 2007 Nov;24(5):489-495.
90. Stoppie N, Wevers M, Naert I. Feasibility of detecting trabecular bone around percutaneous titanium implants in rabbits by in vivo microfocuscomputed tomography. J Microsc 2007 Oct;228(Pt 1):55-61.
91. Le Nihouannen D, Saffarzadeh A, Aguado E, Goyenvalle E, Gauthier O, Moreau F, et al. Osteogenic properties of calcium phosphate ceramics and fibrin glue based composites. J Mater Sci Mater Med 2007 Feb;18(2):225-235.
92. Zheng LW, Wong MC, Rabie AB, Cheung LK. Evaluation of recombinant human bone morphogenetic protein-2 in mandibular distraction osteogenesis in rabbits: Effect of dosage and number of doses on formation of bone. Br J Oral Maxillofac Surg 2006 Dec;44(6):487-494.
93. Simank HG, Stuber M, Frahm R, Helbig L, van Lenthe H, Muller R. The influence of surface coatings of dicalcium phosphate (DCPD) and growth and differentiation factor-5 (GDF-5) on the stability of titanium implants in vivo. Biomaterials 2006 Jul;27(21):3988-3994.
94. Otsuki B, Takemoto M, Fujibayashi S, Neo M, Kokubo T, Nakamura T. Pore throat size and connectivity determine bone and tissue ingrowth into porous implants: three-dimensional micro-CT based structural analyses of porous bioactive titanium implants. Biomaterials 2006 Dec;27(35):5892-5900.
95. Komaki H, Tanaka T, Chazono M, Kikuchi T. Repair of segmental bone defects in rabbit tibiae using a complex of beta-tri calcium phosphate, type I collagen, and fibroblast growth factor-2. Biomaterials 2006 Oct;27(29):5118-5126.
96. Anumula S, Magland J, Wehrli SL, Zhang H, Ong H, Song HK, et al. Measurement of phosphorus content in normal and osteomalacic rabbit bone by solid-state 3D radial imaging. Magn Reson Med 2006 Nov;56(5):946-952.
97. Zakhary K, Motakis D, Hamdy RH, Campisi P, Amar Y, Lessard ML. Effect of recombinant human bone morphogenetic protein 7 on bone density during distraction osteogenesis of the rabbit mandible. J Otolaryngol 2005Dec;34(6):407-414.
98. Giannunzio GA, Speerli RC, Guglielmotti MB. Electrical field effect on peri-implant osteogenesis: a histologic and histomorphometric study. Implant Dent 2008 Mar;17(l):118-126.
99. Laing AJ, Dillon JP, Mulhall KJ, Wang JH, McGuinness AJ, Redmond PH. Statins attenuate polymethylmethacrylate-mediated monocyte activation. Acta Orthop 2008 Feb;79(l): 134-140.
100. Rahbek O, Kold S, Overgaard S, Soballe K. Light microscopic identification and semiquantification of polyethylene particles in methylmethacrylate and paraffin-embedded experimental bone implant specimens. J Microsc 2005 Jun;218(Pt 3):225-232.
101. Wang R, Gao B, Gao Y. Adhesion of osteoblast to new Ti-24Nb-4Zr-7.9Sn alloy. Chinese Journal of Conservative Dentistry 2007;17(5):255-256.
102. Wang R, Gao B, Gao Y, Hao YL, Li SJ. The biological safety evaluation of new Ti-24Nb-4Zr-7.9Sn alloy. Journal of Clinical Stomatology 2007;23:328-331.
103. Kavukcuoglu NB, Denhardt DT, Guzelsu N, Mann AB. Osteopontin deficiency and aging on nanomechanics of mouse bone. J Biomed Mater Res A 2007 Oct;83(l): 136-144.
104. Mittra E, Akella S, Qin YX. The effects of embedding material, loading rate and magnitude, and penetration depth in nanoindentation of trabecular bone. J Biomed Mater Res A 2006 Oct;79(l):86-93.
105. Liu XS, Sajda P, Saha PK, Wehrli FW, Guo XE. Quantification of the roles of trabecular microarchitecture and trabecular type in determining the elastic modulus of human trabecular bone. J Bone Miner Res 2006Oct;21(10):1608-1617.
106. Xu HH, Simon CQ Jr. Fast setting calcium phosphate-chitosan scaffold: mechanical properties and biocompatibility. Biomaterials 2005 Apr;26(12): 1337-1348.
107. Xu HH, Simon CQ Jr. Self-hardening calcium phosphate cement-mesh composite: reinforcement, macropores, and cell response. J Biomed Mater Res A 2004 May l;69(2):267-278.
108. Xu HH, Simon CQ Jr. Self-hardening calcium phosphate composite scaffold for bone tissue engineering. J Orthop Res 2004 May;22(3):535-543.
109. Xu HH, Quinn JB, Takagi S, Chow LC. Synergistic reinforcement of in situ hardening calcium phosphate composite scaffold for bone tissue engineering. Biomaterials 2004 Mar;25(6): 1029-1037.
110.Lin LC, Chen HH, Sun SP. A biomechanical study of the cortex-anchoragevertebral screw. Clin Biomech (Bristol, Avon) 2003 Jul;18(6):S25-32.
111. Vazquez B, Deb S, Bonfield W, Roman JS. Characterization of new acrylicbone cements prepared with oleic acid derivatives. J Biomed Mater Res2002;63(2):88-97.
112.Kettunen J, Makela A, Miettinen H, Nevalainen T, Pohjonen T, Suokas E, etal. The fixation properties of carbon fiber-reinforced liquid crystalline polymerimplant in bone: an experimental study in rabbits. J Biomed Mater Res 2001Jul;56(l):137-143.
113.Rasanen T, Messner K. Estrogen-dependent tensile properties of the rabbitknee medial collateral ligament. Scand J Med Sci Sports 2000 Feb;10(l):20-27.
114.Chen Q, Miyaji F, Kokubo T, Nakamura T. Apatite formation onPDMS-modified CaO-SiO2-TiO2 hybrids prepared by sol-gel process.Biomaterials 1999 Jun;20(12): 1127-1132.
2. Wagner H, Wagner M. Conus hip prosthesis. Acta Chir Orthop Traumatol Cech2001;68(4):213-221.
3. Head WC, Bauk DJ, Emerson RH, Jr. Titanium as the material of choice for cementless femoral components in total hip arthroplasty. Clin Orthop Relat Res 1995Feb(311):85-90.
4. Nakajima H, Okabe T. Titanium in dentistry: development and research in the U.S.A. Dent Mater J 1996 Dec;15(2):77-90.
5. Akagi K, Okamoto Y, Matsuura T, Horibe T. Properties of test metal ceramic titanium alloys. J Prosthet Dent 1992 Sep;68(3):462-467.
6. Pang IC, Gilbert JL, Chai J, Lautenschlager EP Bonding characteristics of low-fusing porcelain bonded to pure titanium and palladium-copper alloy. J Prosthet Dent 1995 Jan;73(l): 17-25.
7. Pang IC, Gilbert JL, Lautenschlager EP, Chai JY Bonding characteristics of low-fusing porcelain to titanium and palladium-copper alloy. Northwest Dent Res 1994 Winter;4(2): 15-16.
8. Esquivel JF, Chai J, Wozniak WT. Color stability of low-fusing porcelains for titanium. Int J Prosthodont 1995 Sep-Oct;8(5):479-485.
9. Esquivel JF, Chai J, Wozniak WT. The physical properties of low-fusing porcelains for titanium. Int J Prosthodont 1996 Nov-Dec;9(6):563-571.
10. Eisenbarth E, Linez P, Biehl V, Velten D, Breme J, Hildebrand HF. Cellorientation and cytoskeleton organisation on ground titanium surfaces. Biomol Eng 2002 Aug;19(2-6):233-237.
11. Bowers KT, Keller JC, Randolph BA, Wick DG, Michaels CM. Optimization of surface micromorphology for enhanced osteoblast responses in vitro. Int J Oral Maxillofac Implants 1992 Fall;7(3):302-310.
12. Kawahara H. Cellular responses to implant materials: biological, physical and chemical factors. Int Dent J 1983 Dec;33(4):350-375.
13. Srimaneepong V, Yoneyama T, Kobayashi E, Doi H, Hanawa T. Comparative study on torsional strength, ductility and fracture characteristics of laser-welded alpha+beta Ti-6Al-7Nb alloy, CP Titanium and Co-Cr alloy dental castings. Dent Mater 2007 Dec 1.
14. Undisz A, Schrempel F, Wesch W, Rettenmayr M. In situ observation of surface oxide layers on medical grade Ni-Ti alloy during straining. J Biomed Mater Res A 2008 Apr 2.
15. Pun DK, Berzins DW. Corrosion behavior of shape memory, superelastic, and nonsuperelastic nickel-titanium-based orthodontic wires at various temperatures. Dent Mater 2008 Feb;24(2):221-227.
16. Suzuki A, Kanetaka H, Shimizu Y, Tomizuka R, Hosoda H, Miyazaki S, et al. Orthodontic buccal tooth movement by nickel-free titanium-based shape memory and superelastic alloy wire. Angle Orthod 2006 Nov;76(6): 1041-1046.
17. Tsao AK, Roberson JR, Christie MJ, Dore DD, Heck DA, Robertson DD, et al. Biomechanical and clinical evaluations of a porous tantalum implant for the treatment of early-stage osteonecrosis. J Bone Joint Surg Am 2005;87 Suppl 2:22-27.
18. Tsao AK, Dias LS, Conway JJ, Straka P. The prognostic value and significance of serial bone scintigraphy in Legg-Calve-Perthes disease. J PediatrOrthop 1997 Mar-Apr; 17(2):230-239.
19. Jandhyala BS, Horn GJ. Minireview: physiological and pharmacological properties of vanadium. Life Sci 1983 Oct 3;33(14): 1325-1340.
20. Hao YL, Li SJ, Sun BB, Sui ML, Yang R. Ductile titanium alloy with low Poisson's ratio. Phys Rev Lett 2007 May 25;98(21):216405.
21. Mostardi RA, Meerbaum SO, Kovacik MW, Gradisar IA, Jr. Response of human fibroblasts to tantalum and titanium in cell culture. Biomed Sci Instrum 1997;33:514-518.
22. Bhattarai SR, Khalil KA, Dewidar M, Hwang PH, Yi HK, Kim HY. Novel production method and in-vitro cell compatibility of porous Ti-6A1-4V alloy disk for hard tissue engineering. J Biomed Mater Res A 2007 Oct 23.
23. Dalmiglio M, Schaaff P, Holzwarth U, Chiesa R, Rondelli G The effect of surface treatments on the fretting behavior of Ti-6A1-4V alloy. J Biomed Mater Res B Appl Biomater 2007 Dec 27.
24. Li SJ, Niinomi M, Akahori T, Kasuga T, Yang R, Hao YL. Fatigue characteristics of bioactive glass-ceramic-coated Ti-29Nb-13Ta-4.6Zr for biomedical application. Biomaterials 2004 Aug;25(17):3369-3378.
25. Li SJ, Yang R, Niinomi M, Hao YL, Cui YY Formation and growth of calcium phosphate on the surface of oxidized Ti-29Nb-13Ta-4.6Zr alloy. Biomaterials 2004 Jun;25(13):2525-2532.
26. Mustafa K, Wennerberg A, Wroblewski J, Hultenby K, Lopez BS, Arvidson K. Determining optimal surface roughness of TiO(2) blasted titanium implant material for attachment, proliferation and differentiation of cells derived from human mandibular alveolar bone. Clin Oral Implants Res 2001 Oct;12(5):515-525.
27. Daugaard H, Elmengaard B, Bechtold JE, Soballe K. Bone growthenhancement in vivo on press-fit titanium alloy implants with acid etched microtexture. J Biomed Mater Res A 2008 Jan 9.
28. Eckardt A, Aberman HM, Cantwell HD, Heine J. Biological fixation of hydroxyapatite-coated versus grit-blasted titanium hip stems: a canine study. Arch Orthop Trauma Surg 2003 Feb;123(l):28-35.
29. Balcik C, Tokdemir T, Senkoylu A, Koc N, Timucin M, Akin S, et al. Early weight bearing of porous HA/TCP (60/40) ceramics in vivo: a longitudinal study in a segmental bone defect model of rabbit. Acta Biomater 2007 Nov;3(6):985-996.
30. Wang H, Eliaz N, Xiang Z, Hsu HP, Spector M, Hobbs LW. Early bone apposition in vivo on plasma-sprayed and electrochemically deposited hydroxyapatite coatings on titanium alloy. Biomaterials 2006 Aug;27(23):4192-4203.
31. Stewart M, Welter JF, Goldberg VM. Effect of hydroxyapatite/tricalcium-phosphate coating on osseointegration of plasma-sprayed titanium alloy implants. J Biomed Mater Res A 2004 Apr
32. Brunski JB. In vivo bone response to biomechanical loading at the bone/dental-implant interface. Adv Dent Res 1999 Jun; 13:99-119.
33. Iezzi G, Scarano A, Petrone G, Piattelli A. Two human hydroxyapatite-coated dental implants retrieved after a 14-year loading period: a histologic and histomorphometric case report. J Periodontol 2007 May;78(5):940-947.
34. Zhu X, Eibl O, Scheideler L, Geis-Gerstorfer J. Characterization of nano hydroxyapatite/collagen surfaces and cellular behaviors. J Biomed Mater Res A 2006 Oct;79(l): 114-127.
35. Wu Y, Yang BC, Deng CL, Tan YF, Zhang XD. The influence of surfacebioactivated modification on titanium percutaneous implants anchored in bone. Int JArtif Organs 2006 Jun;29(6):630-638.
36. Rokkum M, Reigstad A, Johansson CB, Albrektsson T. Tissue reactions adjacent to well-fixed hydroxyapatite-coated acetabular cups. Histopathology of ten specimens retrieved at reoperation after 0.3 to 5.8 years. J Bone Joint Surg Br 2003 Apr;85(3):440-447.
37. Itokawa H, Hiraide T, Moriya M, Fujimoto M, Nagashima G, Suzuki R, et al. A 12 month in vivo study on the response of bone to a hydroxyapatite-polymethylmethacrylate cranioplasty composite. Biomaterials 2007 Nov;28(33):4922-4927.
38. Beekmans HC, Meijer GJ, Barkhuysen R, Blijdorp PA, Merkx MA, Jansen J. The hydroxylapatite-bone interface: 10 years after implant installation. Int J Oral Maxillofac Surg 2008 Apr 8.
39. Eriksson C, Malmberg P, Nygren H. Time-of-flight secondary ion mass spectrometric analysis of the interface between bone and titanium implants. Rapid Commun Mass Spectrom 2008;22(7):943-949.
40. Davidson JA, Daigle KP, Kovacs P. Wear-resistant, hemocompatible Ti-Nb-Zr and Zr-Nb alloys to improve blood pump design and performance. Artif Organs 1996 Jun;20(6):513-522.
41. Davidson JA, Mishra AK, Kovacs P, Poggie RA. New surface-hardened, low-modulus, corrosion-resistant Ti-13Nb-13Zr alloy for total hip arthroplasty. Biomed Mater Eng 1994;4(3):231-243.
42. Gordin DM, Gloriant T, Texier G, Thibon I, Ansel D, Duval JL, et al. Development of a beta-type Ti-12Mo-5Ta alloy for biomedical applications: cytocompatibility and metallurgical aspects. J Mater Sci Mater Med 2004 Aug;15(8):885-891.
43. Hedia HS. Comparison of one-dimensional and two-dimensional functionally graded materials for the backing shell of the cemented acetabular cup. J Biomed Mater Res B Appl Biomater 2005 Aug;74(2):732-739.
44. Krishna BV, Bose S, Bandyopadhyay A. Low stiffness porous Ti structures for load-bearing implants. Acta Biomater 2007 Nov;3(6):997-1006.
45. Lefaix H, Asselin A, Vermaut P, Sautier JM, Berdal A, Portier R, et al. On the biocompatibility of a novel Ti-based amorphous composite: structural characterization and in-vitro osteoblasts response. J Mater Sci Mater Med 2008 May;19(5):1861-1869.
46. Lin DJ, Chuang CC, Chern Lin JH, Lee JW, Ju CP, Yin HS. Bone formation at the surface of low modulus Ti-7.5Mo implants in rabbit femur. Biomaterials 2007 Jun;28(16):2582-2589.
47. Nelea V, Pelletier H, Iliescu M, Werckmann J, Craciun V, Mihailescu IN, et al. Calcium phosphate thin film processing by pulsed laser deposition and in situ assisted ultraviolet pulsed laser deposition. J Mater Sci Mater Med 2002 Dec;13(12):1167-1173.
48. Nicula R, Luthen F, Stir M, Nebe B, Burkel E. Spark plasma sintering synthesis of porous nanocrystalline titanium alloys for biomedical applications. Biomol Eng 2007 Nov;24(5):564-567.
49. Sumitomo N, Noritake K, Hattori T, Morikawa K, Niwa S, Sato K, et al. Experiment study on fracture fixation with low rigidity titanium alloy : Plate fixation of tibia fracture model in rabbit. J Mater Sci Mater Med 2008 Apr;19(4):1581-1586.
50. Xue W, Krishna BV, Bandyopadhyay A, Bose S. Processing and biocompatibility evaluation of laser processed porous titanium. Acta Biomater 2007 Nov;3(6): 1007-1018.
51. Majzoub Z, Finotti M, Miotti F, Giardino R, Aldini NN, Cordioli G. Bone response to orthodontic loading of endosseous implants in the rabbit calvaria: early continuous distalizing forces. Eur J Orthod 1999 Jun;21(3):223-230.
52. Majzoub Z, Berengo M, Giardino R, Aldini NN, Cordioli G. Role of intramarrow penetration in osseous repair: a pilot study in the rabbit calvaria. J Periodontol 1999 Dec;70(12):1501-1510.
53. Weidong Z, Qibin L, Min Z, Xudong W. Biocompatibility of a functionally graded bioceramic coating made by wide-band laser cladding. J Biomed Mater Res A 2008 Jan 9.
54. Ko HC, Han JS, Bachle M, Jang JH, Shin SW, Kim DJ. Initial osteoblast-like cell response to pure titanium and zirconia/alumina ceramics. Dent Mater 2007 Nov;23(ll):1349-1355.
55. Zhao G, Schwartz Z, Wieland M, Rupp F, Geis-Gerstorfer J, Cochran DL, et al. High surface energy enhances cell response to titanium substrate microstructure. J Biomed Mater Res A 2005 Jul l;74(l):49-58.
56. Mahachoklertwattana P, Chuansumrit A, Sirisriro R, Choubtum L, Sriphrapradang A, Rajatanavin R. Bone mineral density, biochemical and hormonal profiles in suboptimally treated children and adolescents with beta-thalassaemia disease. Clin Endocrinol (Oxf) 2003 Mar;58(3):273-279.
57. Boyan BD, Lossdorfer S, Wang L, Zhao G, Lohmann CH, Cochran DL, et al. Osteoblasts generate an osteogenic microenvironment when grown on surfaces with rough microtopographies. Eur Cell Mater 2003 Oct 24;6:22-27.
58. Elias KL, Daehn GS, Brantley WA, McGlumphy EA. An initial study of diffusion bonds between superplastic Ti-6A1-4V for implant dentistry applications. J Prosthet Dent 2007 Jun;97(6):357-365.
59. Zhang LC, Zhou T, Alpay SP, Aindow M, Wu MH. Origin of pseudoelasticbehavior in Ti—Mo-based alloys. Applied Physics Letters 2005;87(24):241909-241903.
60. Li SJ, Cui TC, Hao YL, Yang R. Fatigue properties of a metastable beta-type titanium alloy with reversible phase transformation. Acta Biomater 2008 Mar;4(2):305-317.
61. Bobyn JD, Pilliar RM, Cameron HU, Weatherly GC. Osteogenic phenomena across endosteal bone-implant spaces with porous surfaced intramedullary implants. Acta Orthop Scand 1981;52(2): 145-153.
62. Bobyn JD, Pilliar RM, Cameron HU, Weatherly GC. The optimum pore size for the fixation of porous-surfaced metal implants by the ingrowth of bone. Clin Orthop Relat Res 1980 Jul-Aug(150):263-270.
63. Bobyn JD, Pilliar RM, Cameron HU, Weatherly GC, Kent GM. The effect of porous surface configuration on the tensile strength of fixation of implants by bone ingrowth. Clin Orthop Relat Res 1980 Jun(149):291-298.
64. Boyan BD, Lincks J, Lohmann CH, Sylvia VL, Cochran DL, Blanchard CR, et al. Effect of surface roughness and composition on costochondral chondrocytes is dependent on cell maturation state. J Orthop Res 1999 May;17(3):446-457.
65. Keselowsky BG, Wang L, Schwartz Z, Garcia AJ, Boyan BD. Integrin alpha(5) controls osteoblastic proliferation and differentiation responses to titanium substrates presenting different roughness characteristics in a roughness independent manner. J Biomed Mater Res A 2007 Mar l;80(3):700-710.
66. Marinucci L, Balloni S, Becchetti E, Belcastro S, Guerra M, Calvitti M, et al. Effect of titanium surface roughness on human osteoblast proliferation and gene expression in vitro. Int J Oral Maxillofac Implants 2006 Sep-Oct;21(5):719-725.
67. Martin JY, Dean DD, Cochran DL, Simpson J, Boyan BD, Schwartz Z. Proliferation, differentiation, and protein synthesis of human osteoblast-like cells(MG63) cultured on previously used titanium surfaces. Clin Oral Implants Res 1996Mar;7(l):27-37.
68. Rovensky Yu A, Domnina LV, Ivanova O, Vasiliev JM. Responses of epithelial and fibroblast-like cells to discontinuous configuration of the culture substrate. Membr Cell Biol 2001 Jul;14(5):617-627.
69. Levina EM, Domnina LV, Rovensky YA, Vasiliev JM. Cylindrical substratum induces different patterns of actin microfilament bundles in nontransformed and in ras-transformed epitheliocytes. Exp Cell Res 1996 Nov 25;229(1): 159-165.
70. Rovensky YA. The formation of filopodia-like protrusions during preparation of cell suspensions for scanning electron microscopy. Scanning Microsc 1995;9(4): 1223-1230; discussion 1230-1222.
71. Rovensky Yu A, Samoilov VI. Morphogenetic response of cultured normal and transformed fibroblasts, and epitheliocytes, to a cylindrical substratum surface. Possible role for the actin filament bundle pattern. J Cell Sci 1994 May;107(Pt5):1255-1263.
72. Rovensky YA, Komissarova EV, Topol LZ, Kisseljov FL. Changes in surface relief of suspended cells are morphological signs of the initial stage of neoplastic transformation in fibroblastic monolayer cultures. Cell Biol Int Rep 1992 Jun;16(6):557-565.
73. Piattelli A, Trisi P, Passi P, Piattelli M, Cordioli GP Histochemical and confocal laser scanning microscopy study of the bone-titanium interface: an experimental study in rabbits. Biomaterials 1994 Feb;15(3):194-200.
74. Hartwig D, Harloff S, Liu L, Schlenke P, Wedel T, Geerling G Epitheliotrophic capacity of a growth factor preparation produced from platelet concentrates on corneal epithelial cells: a potential agent for the treatment of ocular surface defects? Transfusion 2004 Dec;44(12): 1724-1731.
75. Hartwig CH, Rehak L, Milz S, Benner KU, Kusswetter W, Willmann G. [Osseointegration of titanium test bodies of different surface properties in metaphyseal bone sites of the dog~a biomechanical and histological analysis]. Biomed Tech (Berl) 1995 Apr;40(4):99-105.
76. Cordioli G, Atiyeh F, Piattelli A, Majzoub Z. Healing of transplanted composite bone grafts-implants: a pilot animal study. Clin Oral Implants Res 2003 Dec;14(6):750-758.
77. Cordioli G, Majzoub Z, Piattelli A, Scarano A. Removal torque and histomorphometric investigation of 4 different titanium surfaces: an experimental study in the rabbit tibia. Int J Oral Maxillofac Implants 2000 Sep-Oct;15(5):668-674.
78. Chierico A, Valentini R, Majzoub Z, Piattelli A, Scarano A, Okun L, et al. Electrically charged GTAM membranes stimulate osteogenesis in rabbit calvarial defects. Clin Oral Implants Res 1999 Oct;10(5):415-424.
79. Abrahamsson I, Albouy JP, Berglundh T. Healing at fluoride-modified implants placed in wide marginal defects: an experimental study in dogs. Clin Oral Implants Res 2008 Feb;19(2):153-159.
80. Abrahamsson I, Cardaropoli G. Peri-implant hard and soft tissue integration to dental implants made of titanium and gold. Clin Oral Implants Res 2007 Jun;18(3):269-274.
81. Abrahamsson I, Berglundh T. Tissue characteristics at microthreaded implants: an experimental study in dogs. Clin Implant Dent Relat Res 2006;8(3):107-113.
82. Abrahamsson I, Berglundh T, Linder E, Lang NP, Lindhe J. Early bone formation adjacent to rough and turned endosseous implant surfaces. An experimental study in the dog. Clin Oral Implants Res 2004 Aug;15(4):381-392.
83. Abrahamsson I, Berglundh T, Sekino S, Lindhe J. Tissue reactions to abutment shift: an experimental study in dogs. Clin Implant Dent Relat Res 2003;5(2):82-88.
84. Tsutsumi R, Hock C, Bechtold CD, Proulx ST, Bukata SV, Ito H, et al. Differential effects of biologic versus bisphosphonate inhibition of wear debris-induced osteolysis assessed by longitudinal micro-CT. J Orthop Res 2008 Apr 10.
85. Xu S, Lin K, Wang Z, Chang J, Wang L, Lu J, et al. Reconstruction of calvarial defect of rabbits using porous calcium silicate bioactive ceramics. Biomaterials 2008 Jun;29(17):2588-2596.
86. Voor MJ, Yang S, Burden RL, Waddell SW. In vivo micro-CT scanning of a rabbit distal femur: repeatability and reproducibility. J Biomech 2008;41(l):186-193.
87. Anumula S, Magland J, Wehrli SL, Ong H, Song HK, Wehrli FW. Multi-modality study of the compositional and mechanical implications of hypomineralization in a rabbit model of osteomalacia. Bone 2008 Feb;42(2):405-413.
88. Zhang G, Qin L, Sheng H, Yeung KW, Yeung HY, Cheung WH, et al. Epimedium-derived phytoestrogen exert beneficial effect on preventing steroid-associated osteonecrosis in rabbits with inhibition of both thrombosis and lipid-deposition. Bone 2007 Mar;40(3):685-692.
89. Swieszkowski W, Tuan BH, Kurzydlowski KJ, Hutmacher DW. Repair and regeneration of osteochondral defects in the articular joints. Biomol Eng 2007 Nov;24(5):489-495.
90. Stoppie N, Wevers M, Naert I. Feasibility of detecting trabecular bone around percutaneous titanium implants in rabbits by in vivo microfocuscomputed tomography. J Microsc 2007 Oct;228(Pt 1):55-61.
91. Le Nihouannen D, Saffarzadeh A, Aguado E, Goyenvalle E, Gauthier O, Moreau F, et al. Osteogenic properties of calcium phosphate ceramics and fibrin glue based composites. J Mater Sci Mater Med 2007 Feb;18(2):225-235.
92. Zheng LW, Wong MC, Rabie AB, Cheung LK. Evaluation of recombinant human bone morphogenetic protein-2 in mandibular distraction osteogenesis in rabbits: Effect of dosage and number of doses on formation of bone. Br J Oral Maxillofac Surg 2006 Dec;44(6):487-494.
93. Simank HG, Stuber M, Frahm R, Helbig L, van Lenthe H, Muller R. The influence of surface coatings of dicalcium phosphate (DCPD) and growth and differentiation factor-5 (GDF-5) on the stability of titanium implants in vivo. Biomaterials 2006 Jul;27(21):3988-3994.
94. Otsuki B, Takemoto M, Fujibayashi S, Neo M, Kokubo T, Nakamura T. Pore throat size and connectivity determine bone and tissue ingrowth into porous implants: three-dimensional micro-CT based structural analyses of porous bioactive titanium implants. Biomaterials 2006 Dec;27(35):5892-5900.
95. Komaki H, Tanaka T, Chazono M, Kikuchi T. Repair of segmental bone defects in rabbit tibiae using a complex of beta-tri calcium phosphate, type I collagen, and fibroblast growth factor-2. Biomaterials 2006 Oct;27(29):5118-5126.
96. Anumula S, Magland J, Wehrli SL, Zhang H, Ong H, Song HK, et al. Measurement of phosphorus content in normal and osteomalacic rabbit bone by solid-state 3D radial imaging. Magn Reson Med 2006 Nov;56(5):946-952.
97. Zakhary K, Motakis D, Hamdy RH, Campisi P, Amar Y, Lessard ML. Effect of recombinant human bone morphogenetic protein 7 on bone density during distraction osteogenesis of the rabbit mandible. J Otolaryngol 2005Dec;34(6):407-414.
98. Giannunzio GA, Speerli RC, Guglielmotti MB. Electrical field effect on peri-implant osteogenesis: a histologic and histomorphometric study. Implant Dent 2008 Mar;17(l):118-126.
99. Laing AJ, Dillon JP, Mulhall KJ, Wang JH, McGuinness AJ, Redmond PH. Statins attenuate polymethylmethacrylate-mediated monocyte activation. Acta Orthop 2008 Feb;79(l): 134-140.
100. Rahbek O, Kold S, Overgaard S, Soballe K. Light microscopic identification and semiquantification of polyethylene particles in methylmethacrylate and paraffin-embedded experimental bone implant specimens. J Microsc 2005 Jun;218(Pt 3):225-232.
101. Wang R, Gao B, Gao Y. Adhesion of osteoblast to new Ti-24Nb-4Zr-7.9Sn alloy. Chinese Journal of Conservative Dentistry 2007;17(5):255-256.
102. Wang R, Gao B, Gao Y, Hao YL, Li SJ. The biological safety evaluation of new Ti-24Nb-4Zr-7.9Sn alloy. Journal of Clinical Stomatology 2007;23:328-331.
103. Kavukcuoglu NB, Denhardt DT, Guzelsu N, Mann AB. Osteopontin deficiency and aging on nanomechanics of mouse bone. J Biomed Mater Res A 2007 Oct;83(l): 136-144.
104. Mittra E, Akella S, Qin YX. The effects of embedding material, loading rate and magnitude, and penetration depth in nanoindentation of trabecular bone. J Biomed Mater Res A 2006 Oct;79(l):86-93.
105. Liu XS, Sajda P, Saha PK, Wehrli FW, Guo XE. Quantification of the roles of trabecular microarchitecture and trabecular type in determining the elastic modulus of human trabecular bone. J Bone Miner Res 2006Oct;21(10):1608-1617.
106. Xu HH, Simon CQ Jr. Fast setting calcium phosphate-chitosan scaffold: mechanical properties and biocompatibility. Biomaterials 2005 Apr;26(12): 1337-1348.
107. Xu HH, Simon CQ Jr. Self-hardening calcium phosphate cement-mesh composite: reinforcement, macropores, and cell response. J Biomed Mater Res A 2004 May l;69(2):267-278.
108. Xu HH, Simon CQ Jr. Self-hardening calcium phosphate composite scaffold for bone tissue engineering. J Orthop Res 2004 May;22(3):535-543.
109. Xu HH, Quinn JB, Takagi S, Chow LC. Synergistic reinforcement of in situ hardening calcium phosphate composite scaffold for bone tissue engineering. Biomaterials 2004 Mar;25(6): 1029-1037.
110.Lin LC, Chen HH, Sun SP. A biomechanical study of the cortex-anchoragevertebral screw. Clin Biomech (Bristol, Avon) 2003 Jul;18(6):S25-32.
111. Vazquez B, Deb S, Bonfield W, Roman JS. Characterization of new acrylicbone cements prepared with oleic acid derivatives. J Biomed Mater Res2002;63(2):88-97.
112.Kettunen J, Makela A, Miettinen H, Nevalainen T, Pohjonen T, Suokas E, etal. The fixation properties of carbon fiber-reinforced liquid crystalline polymerimplant in bone: an experimental study in rabbits. J Biomed Mater Res 2001Jul;56(l):137-143.
113.Rasanen T, Messner K. Estrogen-dependent tensile properties of the rabbitknee medial collateral ligament. Scand J Med Sci Sports 2000 Feb;10(l):20-27.
114.Chen Q, Miyaji F, Kokubo T, Nakamura T. Apatite formation onPDMS-modified CaO-SiO2-TiO2 hybrids prepared by sol-gel process.Biomaterials 1999 Jun;20(12): 1127-1132.